The present invention relates to a flexible intermediate bulk container (FIBC) for lifting, transportation and storage of bulk material. The FIBC is formed by inserting one half of a hose-like blank into another half thereof, thus forming an inner sack and an outer sack. The FIBC includes a suitable common or separate bottom, and at least one lifting loop. The invention relates also to a process of manufacturing such flexible container. The flexible container is intended as a container for lifting, transportation and storage of bulk material such as powderous granular fertilizer, ground or unground grain, Portland cement, coal, etc., in quantities of several hundred kilos per container.
There is known a sack-like container for transportation of bulk material from, e.g., SE Patent Specification No. 420,704, where one half of a hose-like blank is inserted through a slot into the other half to form outer and inner sacks. The middle of the hose-like blank forms in the finished product a material loop at the top section of the container. This material loop is used as a lifting eye during transportation and lifting of the flexible container. Such lifting eye formed by a material loop from the inner sack partly crosses the longitudinal axis of the container below a lifting means and continues as an integral part of the outer sack. When the container is filled, this crossing will contribute to a contraction of the opening in the lifting eye. This complicates the application of the lifting means to such a degree that one has to do the operation manually. The contractions of the lifting eye will be more severe if the container is filled up to a maximum extent. The contractions of the lifting eye increase the stress and strain on the material of the container and thus reduce the carrying capacity of the container. To make use of such container, the material loop forming the lifting eye has to be made relatively long. This results in the ratio between the carrying capacity and the material consumption being decreased, whereas the manufacturing costs are increased correspondingly. In addition, the relatively long material loop results in reduced ability for transportation and storage of this type of flexible container in places with restricted headroom.